Thromboembolism and bleeding in patients with cancer and mechanical heart valves

Mechanical heart valves (MHV) require life-long anticoagulation with vitamin K antagonists (VKA), but anticoagulation management is complex in patients with cancer due to a high risk of thrombosis and bleeding. This is a retrospective, single-center study to assess anticoagulation management and thrombotic (stroke/valve thrombosis) and bleeding events in patients with active cancer and MHV. The incidence of thrombotic complications was compared to a control group (matched 1:1) of patients with MHV but without cancer. We included 48 patients, 60% of whom had aortic prostheses, 23% mitral prostheses and 17% both types. All patients received VKA as anticoagulant. With a median follow-up of 5.12 years, we observed two arterial thrombotic events (two strokes and no heart valve thrombosis). The 5-year incidence (95% confidence interval [CI]) of stroke/valve thrombosis was 5.7% (0.9-17.9%). The control group had a similar incidence of stroke/valve thrombosis (5-year incidence 7.9% [95%CI 2-19.8], p = 0.16). There were also 15 major bleeding episodes in the cancer group, 11 of which were related to a surgical procedure. The 5-year incidence (95% CI) of major bleeding was 32.9% (18.5-48%), and that of major bleeding unrelated to any procedure was 10.3% (3-23%). We found a low incidence of thrombotic events in this series of patients with active cancer and MHV who were anticoagulated with VKA. However, the incidence of bleeding was high, particularly in relation to invasive procedures.